Know what platform you want to use, choose multi-admin sites because it allows for the most flexibility if adding additional sites. If you are planning on adding SSL, consider purchasing it directly through Site5 rather than an outside vendor, installation was anything but straightforward. Be prepared for some downtime (a few hours a month) but also know they work around the clock to get it back up and running. They are great communicators as long as you are proactive, ask questions because they are always willing to answer and are extremely knowledgeable.
After reading reviews we chose site5 because of its customer service and quick response to issues. They are always available via online chat and the reps are extremely knowledgeable, friendly, and helpful. We use SSL, basic hosting, backup. Even though I manage and run the websites, I don't know everything. Several times Site5 reps have walked me through an issue and given me guided help. I've learned more about web hosting and troubleshooting issues through their insightful answers.
I like the options they offer as far as website building tools, the ease of additional installation of web building applications, and of course the phenomenal customer service they provide.
I would like if the back office was a little more intuitive. Luckily customer service is quick and helpful because there have been many times I am trying to do what should be a fairly simple task and it is complicated by the maze of links I have to click.